Tranny takes 4 quarts of Dexron III ATF such as
AMSOIL ATF. Diff takes two quarts of synthetic 75w90. AMSOIL just released
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 last fall which is well suited to our diff.
To change the tranny and diff fluid I put the car up on Rhino ramps.
Tranny drain plug is on lower passenger rear corner of tranny. Fill plug is center line driver's side about 2/3 the way to the top. The tranny temp plug goes into this same spot.
Diff drain plug is on the bottom of the diff by the leaf spring. The fill plug is in the upper right on the back. This takes an allen wrench, 6mm I think.
Although I know you are looking for another fluid, I feel the AMSOIL ATF and gear lubes are outstanding products. In my race this past weekend, I lost the differential axle half shaft seal on the diff halfway through the 26 lap race and lost at least a quart of my diff fluid. The diff got so hot I got a tranny high temp warning with 6 laps to go despite my tranny cooler... and that temp is taken from the tranny cooler return, so who knows how hot the tranny and diff really were (tranny warning comes in at 277 degrees). Despite these extreme temps, I was leading the National race and pressed on to the finish and both the diff and tranny worked fine through the checkered flag.
As a precaution, I'm going to have my tranny and diff rebuilt now. They both have three and a half total years, two and a half years of racing, and 16k total miles.